The goal of this project is to guide the development of health policy regarding the optimal use of genetic screening tests designed to detect carriers of cystic fibrosis (CF). These policies should be based on the ability of various screening strategies to achieve clinical goals, and on the economic, social, and psychologic costs incurred by these strategies in accomplishing those goals. This project will illuminate the tradeoffs required by the different clinical strategies in order to shape public policy. This project will accomplish these goals through the use of a decision model of the main alternatives for CF carrier screening programs. The decision model developed in this project will be designed to answer the following specific questions: [1] Should CF carrier screening target the deltaF508 mutation only, or should it target other known mutations as well? [2] Should carrier screening be performed on both partners in a couple, or just one? [3] If performed on both partners, should carrier screening be performed in parallel, with both partners in a couple tested simultaneously, or should it be performed in series, with the second partner tested only for certain test results from the first partner? [4] What is the best course and sequence of further testing and treatment following alternative carrier screening results? [5] Should individuals who have been screened in the past for CF mutations be rescreened as more mutations are uncovered? [6] What is the anticipated impact of future technologic innovation in the detection of CF carriers, in prenatal diagnosis, or in the treatment of CF? [7] What tradeoffs between monetary and nonmonetary effects do the alternative answers to these questions imply? [8] How will the answers to these questions differ among patients, health care providers, and insurance companies, who have different financial, psychologic, and moral perspectives? Different carrier screening strategies will be judged according to their effects on four outcomes central to the policy decisions that need to be made: The first outcome is the number of CF births that result; the second outcome is the number of unaffected births that result; the third outcome is the number of pregnancy terminations that result; the fourth outcome is the dollar cost of the program. Different strategies will have different impacts on each of these four outcomes. The decision model we build will help us understand these tradeoffs so policy makers can make informed choices. Screening strategies for many genetic diseases face similar tradeoffs: Should we screen for many mutations, or just the most common? Should we screen both partners in a couple, or just one? CF carrier screening represents a current and vivid example of this problem, but many other genetic disease will raise similar questions. This project will help us to understand the implications of these tradeoffs for CF, as well as for many other genetic conditions that are likely to receive increasing attention because of advances stemming from the Human Genome Project.